Patent GB-990636-A (GB)
Title: New lead complexes containing phosphorus and nitrogen
Inventor: TWITCHETT HARRY JAMES
IPC: C07F7/28
Filed: 1961-09-27
Abstract: The invention comprises co-ordination complexes of a lead salt of a thio acid of phosphorus of the formula <FORM:0990636/C2/1> <FORM:0990636/C2/2> and <FORM:0990636/C2/3> wherein R and R1 are hydrocarbon or sub-stituted hydrocarbon radicals which may be the same or different, or taken together represent an alkylene radical which may be interrupted in the chain by a hetero atom such as oxygen or sulphur and which together with the remainder of the thio acid molecule forms a ring structure containing 8 to 10 atoms in the ring, and X is sulphur or oxygen with a heterocyclic tertiary amine selected from a group comprising heterocyclic tertiary amines in which one nitrogen atom is common to two rings and heterocyclic ditertiary amines in which the nitrogen atoms which may or may not be in the same ring and of which one may be exocyclic are separated from one another by either two or three carbon atoms.  They may be obtained by mixing together solutions or suspensions containing appropriate stoichiometric proportions of the lead compound and the tertiary amine and optionally heating the mixture, e.g. by warming or boiling the mixture under reflux.  The reaction may suitably be carried out in a solvent e.g. acetone, petroleum ether, toluene or cyclohexanone. The radicals R and R1 may be alkyl groups containing 6 or more carbon atoms, cycloalkyl, aryl, aralkyl or an alkyl group interrupted by one or more hetero atoms e.g. oxygen or sulphur and R and R1 taken together may for example be hexamethylene or the radical -CH(CH3)CH2OCH2CH(CH3)-. Specified heterocyclic tertiary amines are quinuclidine, 1,4 - diaza - bicyclo - (2,2,2)-octane (i.e. triethylenediamine), pyrrolizidine, 7 - oxa - 1 - aza - bicyclo - (4,3,0) - nonane, 4 - dimethylamino - pyridine, 4 - di - n - butylamino pyridine, 4 - morpholinopyridine, 4 - pyrrolidinopyridine, N,N1 - dimethylpiperazine, 1,10-phenanthroline, 2,21 - dipyridyl and N,N1 - dimethyl - 1:4 - diazacycloheptane.  Examples are given for the production of (1) and (2) a coordination complex of one molecule of lead dinonyl (or dicyclohexyl) dithiophosphate with 2 molecules of 4-dimethylaminopyridine: (3) and (4) a co-ordination complex of one molecule of lead di(cyclohexyl) dithiophosphate with 2 molecules of triethylene diamine and with one molecule of 2,21-dipyridyl respectively.  The products are useful as catalysts for the preparation of urethanes from organic isocyanates and hydroxyl-group containing compounds as described in Specification 990,635.  Lead dinonyl dithiophosphate is obtained by reacting 3,5,5-trimethylhexanol with phosphorus pentasulphide at 70 DEG  C. to form the corresponding dinonyldithiophosphoric acid which is then reacted with litharge in chloroform. Lead dicyclohexyl dithiophosphate is obtained in a similar manner by reacting cyclohexanol with phosphorus pentasulphide at 75 \sB 2 DEG  C. to form dicyclohexyl dithiophosphoric acid and reacting the latter with lead oxide in chloroform. Lead dialkyl thiophosphates may be obtained from the sodium salts prepared by reacting a dialkyl phosphite with a sodium alkoxide and sulphur and lead salts of diaryldithiophosphinic acids may be obtained from the free acids prepared by reacting phosphorus pentasulphide and an aromatic hydrocarbon in the presence of aluminium chloride.